Ways of leveling alt jobs from 70 to 80 efficiently? ?

[DenzelVilliers]

Rolettes for Daily Bonus then DUNGEONS after, select the highest Lv Dungeon for your Job and farm it ( don't go for end-game Lv50/60/70 Dungeons, the EXP in there isn't high ).

Fates aren't a big deal at all, each Dungeon wave gives you more EXP than Fates and it's faster to clear, Fates take many time to clear, you must keep running around all Map to reach it, you must wait until the next spawn and gives less EXP to you.

Lv70: go to Castrum Abania until Lv71.
Lv71: go to Holminster Switch until Lv73.
Lv73: go to Dohn Mheg until Lv75.
Lv75: go to The Qitana Ravel until Lv77.
Lv77: go to Malikah's Well until Lv79.
Lv79: go to Mt. Gulg until Lv80.

[Mirassou]

Rolettes for Daily Bonus then DUNGEONS after, select the highest Lv Dungeon for your Job and farm it ( don't go for end-game Lv50/60/70 Dungeons, the EXP in there isn't high ).

Fates aren't a big deal at all, each Dungeon wave gives you more EXP than Fates and it's faster to clear, Fates take many time to clear, you must keep running around all Map to reach it, you must wait until the next spawn and gives less EXP to you.

Lv70: go to Castrum Abania until Lv71.
Lv71: go to Holminster Switch until Lv73.
Lv73: go to Dohn Mheg until Lv75.
Lv75: go to The Qitana Ravel until Lv77.
Lv77: go to Malikah's Well until Lv79.
Lv79: go to Mt. Gulg until Lv80.

And if you don't care about being efficient (because my suggestion definitely takes a longer) and if you like and plan to use the Trust system, you can do the above to level your Trust NPC's as well.